Fuel-feeder for furnaces.



PATENTED MAY 9. 1905.

E. N. SPEAR. FUEL EEEDEE FOR EURNACES.

APPLICATION 4IE'ILIED SEPT. 12,1901.

2 SHEETS-SHEET 2,.

Patented May 9, 1905.

FFICIQ.

FRANK N. SPEAR7 OF LOS ANGELES, CALIFORNIA.

FUEL-FEEDER FOR FURNACES.

SPECIFICATION forming part of Letters Patent No. 789,677, dated May 9, 1905.

Application filed September 12, 1901. Serial No. 75.138.

To all wiz/0m, it may concern:

Be it known that I, FRANK N SPEAR, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented an Improvement in Fuel-Feeders for Furnaces, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My invention has for its object to improve apparatus for feeding fine or pulverized coal or fuel to furnaces for steam-boilers and the like, my invention relating to apparatus of the general type shown and described in Letters Patent of the United States issued to me under date of August 7, 1900, No. 655,464.

In order that my invention may be understood, I will rst disclose the same in connection with one form of apparatus made in accordance therewith.

Referring to the drawings, Figure l in vertical section, partial elevation, illustrates one form of apparatus made in accordance with my invention; Fig. 2, a left-hand or front elevation of the delivering apparatus shown in Fig. l, the automatic appliances being omitted in this figure for the sake of clearness; and Fig. 3, an enlarged sectional detail of the end of the delivery device.

In the particular embodiment of my invention selected for illustration herein and shown in the drawings, A is a fuel-supply chamber that may be the end of a conduit or chute leading from a hopper or coal-supplying device, or it may be hopper-shaped, as here shown, to receive directly thereinto the fuel from the bins, cars, or other source of supply.

Within the supply-chamber A, and preferably near the bottom thereof, is arranged a rotary feeding and loosening device a, shown as composed of a shaft a, surrounded by a tubular casing or barrel a2, perforated to receive a plurality of feeding and loosening members or pins a3. These pins, as shown, are cut of uniform length and are driven through the openings of the shell or barrel a2 until they contact with the shaft a', thus insuring uniform projection of the said. pins.

For the best results these pins are staggered throughout the length of the device.

In the bottom of the supply-chamber A is l form of a cylinder or barrel c, mounted at its ends upon suitable ournals and provided at its periphery with a series of longitudinal vanes or wings c, which during rotation of the device project the fuel contained in the said supply-chamber into the combustion-chamber to be consumed therein, In the present construction the vanes or wings c of the delivery device are shown as made of comparatively thin sheets of metal folded along their middle lines and inserted in longitudinallyarranged grooves in the cylinder or barrel c, they being confined in said grooves by locking-strips c2, driven thereinto and held frictionally or otherwise, as desired. In the present construction the said locking-strips (see Fig. 3) are prolonged beyond the ends of the vanes or wings c and are secured by rings c3, that encircle the ends thereof.

The communication a4 between the supply-chamber A and the delivery-chamber I) has a movable wall, herein shown as formed by a roller d, ournaled in suitable bearings in the side walls of the delivery-chamber. Opposed to this movable wall d is a controlling device e, shown in the form of a gate carried by a support fulcrumed at e, the said gate or controlling device having a movement toward and from the movable wall of said communication a4 for the purpose of regulating the areal of the said communication and the resultant quantity of material permitted to pass therethrough from the supply-chamber to the delivery-chamber. For moving this controlling device I have here provided a hand-wheel e2 upon the end of a shaft e3, having a threaded portion e4 tapped into the front wall of the supply-chamber, with its end extended through an opening in the support for said controlling device and provided at opposite sides thereof with washers or lugs e5 e, whereby in-and-out movement of the said shaft, due to rotation thereof by said hand-wheel, operates to move the said controlling device about its said fulcrum to open and close, more or less, the said passage or communication a4.

In practice the feed and clearing device a and the delivery device C may be rotated in any suitable or desired manner; but for convenience one may be rotated from the otherby suitable worm or gearing, as shown in Fig. 2, and wherein a worm-wheelj'on one of the journals of the feeding and clearing de'- vice meshes with a worm f', that carries a beveled pinion f2, meshing with a beveled pinion f3 on the journal of the delivery device C, the latter having a suitable drivingpulley f4, which may be belted to any convenient counter-shaft or motor for driving. I prefer also to rotate the roller d at a slow rate of s eed in order to avoid possible clogging of t e material in the communication a4 between the two chambers, and this may conveniently be done by belting it, as by a belt g, to a pulley on the journal of thevfeeding and clearing device a (see Fig. 2) or otherwise, at the convenience of the operator. I also provide said roller d with a hand-wheel g', by which said roller may be rotated to cause movement of the movable wall here formed by said roller manually and independently of any other drivin means which may be employed. In fact, tTie manual operation of said roller or wall may alone be depended upon, if desired.

The operation of the apparatus is as follows, viz 2A Fuel of the desired degree of lineness, such as dust-coal, is deposited in the supply-chamber A and is kept constantly loosened near the bottom of said chamber by the rotary device a, which also acts as a feeder to furnish constant feed or flow of the material to the controlled communication a4, leadinfy to the delivery-chamber. amount of material permitted to pass to the delivery-chamber is determined by the controlling device or gate e, and clogging of the material in the communication a4 is guarded against and prevented by the movable wall here formed by the roller d. The material received into the delivery chamber b is caught by the rapidly-revolving delivery device C and is projected into the combustionchamber of the furnace in such a manner as to ignite readily therein and burn in a manner well understood by those conversant with the art. Air in suitable quantities is The v admitted to the delivery-chamber through an opening h in the upper portion thereof and an opening h below the said chamber, one or both of which may, if desired, be controlled or adjusted as to area in any suitable or desired manner. (Not herein shown.) The air thus admitted to the delivery-chamber is mixed with the fuel by the action of the delivery device rotating therein, so as to provide the most efficient mixture of fuel and air for the best combustion and highest efficiency within the combustion-chamber.

The apparatus as here described may be successfully operated, depending alone upon manual adjustment and control of the various parts but for convenience automatic means may be employed for the purpose,

and I have here shownone form of automatic control which I will now describe.

M is a pressure-responsive device of any suitable or .desired construction (here shown as a cylinder m) in communication by a pipe m with the boiler, whereby boiler-pressure is admitted to said cylinder, where it acts upon a piston m2, opposed by a spring m3, and moves said piston along more or less within its said cylinder, according to thepressure within the boiler. The piston m2 has a piston-rod m4 connected at its upper end in suitable manner with a vibrating lever m5, fulcrumed at m. This lever at its opposite ends is connected by cords or other flexible connections m7 m8 with a drum m, fast on the shaft e3, that controls the position of the controlling device or gate e, one of the said cords being wound about and upon said drum in one direction and the other cord in an opposite direction. sure within the boiler rises it will act to move the piston mi. forward within its cylinder fm, and thereby rock the lever m5 in a direction to rotate said shaft e3 to move said gate e to close more or less the passage or communication a4. This reduces the amount of fuel permitted to pass to the delivery device, and consequently reduces the heating effect within the combustion-chamber. As the pressure within the boiler falls the piston m2 will be returned within its said cylinder by the spring m3, causing opposite movement of the said lever m5 and opposite rotation of said shaft e3, thereby to open more or less the said passage a4 and increase the amount of fuel delivered to the combustionchamber, and consequently increase the resultant heating effect within said combustion-chamber. Thus the apparatus may be strictly automatic, and because of the nature of the fuel used and the efficiency of the apparatus disclosed close regulation may at all times be had.

The roller d, which forms the movable wall for the controlled passa e aA1 in the construction here shown, may e said to constitute one form of clearing device. because by its IOO As the steam-presj rotation at any time it operates as a clearer to free the said passage a4.

F or most efficient operation the fuel particles should be delivered to the combustion-chamber in an individualized or separated condition surrounded each by an atmosphere or film of oxygen, Owing to the tendency of the pulverulent fuel to pack or agglomerate wherever the fuel particles are allowed to accumulate or come together in masses, this result is ordinarily difficult to attain, the tendency being for the associated masses to adhere in their passage to and after entrance into the combustion-chamber. In the embodiment of my invention herein described, however, the fuel which is assembled in mass in the hopper is agitated and freed in the most effective position at or about the entrance to the passage leading to the delivery-chamber, so thatthe same starts on its passage in an individualized condition, in which condition, too, and therefore through the cooperation of the agitator, the movable clearing-wall is best fitted to act upon the fuel to assist its passage into the delivery-chamber. It is also to be observed that the location of the delivering device relatively to the fuel-passage and the movable wall is such that the fuel is received by the former immediately on its entrance into the delivery-chamber while still in motion and without opportunity to accumulate or pack and immediately upon entrance delivered to the combustion-chamber at a uniform rate and in the most efficient condition for combustion. It is to be further observed that the automatic control of the rate of fuel delivery is such that it does not lead to the ag- ,glomeration of any of the fuel particles in transit. y

While I have here disclosed one embodiment of my invention, said invention is not limited to the embodiment disclosed, for it may be varied within the spirit and scope of the invention.

Having described my invention and without limiting myself as to details, what I- .elaim, and desire to secure by Letters Patent, is-

1. In a pulverulent-fuel-feeding device, feeding means for feeding the fuel to the combustion-chamber comprising a fuel-supply chamber, a delivery-chamber communicating therewith through an open gravity-fed passage to provide an open uninterrupted communication between the delivery and fuel-supply chambers, a movable clearingwall for said passage to maintain and assist the constant supply of fuel therethrough, and agitating means cooperating with and in close proximity to said movable wall and said passage to prevent the agglomeration of the fuel particles near the latter and to permit the effective action upon the same by the said movable wall.

2. In a pulverulent-fuel-feeding device, feeding means for feeding the fuel to the combustion-chamber comprising a fuel-supply chamber, a delivery-chamber communicating therewith through an open supply-passage to provide uninterrupted communication between the delivery and fuel-supply chambers, agitating means to maintain the separation and prevent the agglomeration of the fuel particles at the supply-passage, a movable clearing-wall for said passage to assist the movement of the separated fuel particles therethrough and mechanical delivery means for receiving the fuel directly from said passage and movable Wall in its separated condition and delivering the same to the combustion-chamber also in a separated or individualized condition.

3. In a pulverulent-fuel-feeding device, fuel-feeding means for feeding the fuel to the combustion-chamber comprising a fuel-supply chamber, a delivery-chamber communicating therewith through a supply-passage adapted to restrict and measure the fuel passing therethrough, a movable clearing-wall for said passage`to assist the movement of the fuel therethrough, agitating means in close proximity to said supply-passage to maintain the separation lof the individual fuel particles thereat, and mechanical delivery means to receive the fuel particles in their individualized condition on their emergence froml the supply-passage and to deliver the same into the combustion-chamber.

4L. In a pulverulent-fuel-feeding device, feeding means for feeding fuel to the combustion-chamber comprising a fuel-supply chamber, a delivery-chamb er communicating therewith through a supply-passage adapted to restrict and measure the amount of fuel passing therethrough, means for varying the area of said passage to control the flow of fuel therethrough, a movable clearing-wall forsaid passage to assist the movement of fuel therethrough, and agitating means cooperating With and in close proximity to said movable wall and said passage to separate or individualize the fuel particles passing therethrough and permit effective action of the movable wall upon the separated fuel particles.

5. In a pulverulent-fuel-feeding device, fuel-feeding means for feeding fuel to the combustion-chamber comprising a fuel-supply chamber, a delivery-chamber communieating therewith through an open uninterrupted supply-passage to provide an open uninterrupted communication between the delivery and fuel-supply chambers, a movable clearing-wall for said passage to assist and maintain the constant supply of fuel therethrough, delivery means within said delivery-chamber to receive the fuel particles from the said passage and movable wall in their individualized or separaetd condition and to deliver them in such condition to the IOO IIO

combustion-chamber, and means'for varying the area of the supply-passage to control the flow of fuel therethrough.

6. In a pulverulent-fuel-feeding device, feeding means for feeding the fuel to the combustion-chamber comprising a supplychamber, a delivery-chamber, a supply-passage between the two, mechanical means within said delivery-chamber to receive the fuel from said passage and deliver the same in an individualized or separated dust-like condition to the combustion-chamber, and means responsive to changes in boiler conditions for controlling the area of the supplypassage.

7. In a pulverulent-fuel-feeding device, feeding means for feeding the fuel to the combustion-chamber comprising a supplychamber, a delivery-chamber, an open supply-passage to provide an open uninterrupted communication between the delivery and fuel-supply chambers and permit the passage of the pulverulent fuel therethrough in an individualized state, delivery means within the chamber to receive the fuel as it emerges from the supply-passage in its individualized or separated condition and to maintain and deliver it in like condition to the combustion-chamber, and means responmaintain the movement of the pulverulent fuel throughout its course from the supplychamber to the combustionchamber in an individualized or separated conditionof the fuel particles.

9. In a pulverulent -fuel-feedmg device, feeding means for feeding the fuel to the combustion-chamber comprising a fuel-supply chamber, a delivery-chamber -communicating therewith through an open supplypassage to provide an uninterrupted communication between the delivery and fuel-supply chambers, a movable clearing-wall for said passage to maintain and assist the constant supply of fuel therethrough, and derivery means to receive the fuel particles on emergence from the said passage and while in their individualized condition and to deliver the same into the combustion-chamber in like condition.

10. In a pulverulent-fuel-feeding apparatus a supply-chamber provided with a feeding and loosening device comprising a shaft, a barrel surrounding the same but having an annular space between said shaft and barrel, and loosening and feeding pins inserted through the barrel against said shaft, as described. y

11. In a pulverulent-fuel-feeding apparatus a supply-chamber provided with a feeding and Yloosening device comprising a shaft, a surrounding barrel, and loosening and feeding pins inserted eXteriQrly through the latter against said shaft, as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FRANK N. sPEAE.

Witnesses:

FREDERICK L. EMERY, A. E. CHEsLEY. 

